Managing indoor comfort and maintaining air quality in a heatwave

Those of you who have invested in a low energy house with good air tightness, high levels of insulation and a Mechanical Ventilation with Heat Recovery (MVHR) system will benefit from this decision both in Winter and also in Summer.

Houses with an MVHR system are in a better position than houses without one in times of a heatwave. The current advice is to leave windows closed during the day which prevents warm air from outside entering the home. You can be happy with this, knowing that you have more than adequate volumes of fresh filtered air being introduced to your house via a heat exchange system.

ProAir recommends the following to optimize comfort in your home:

During the day –

  • Close blinds and/or curtains
  • Operate your MVHR system at normal speed

Houses with Heat Recovery Ventilation can remain comfortable. Indoor air exhausting through the system will cool down incoming hot air to a similar level to that of the indoor temperature.

At night –

  • Open windows
  • Operate your MVHR system at normal speed

This will help lower the indoor air temperature as much as possible in preparation for the following day.

The latest research findings indicate that this is the most appropriate strategy to utilize MVHR and manage indoor comfort during periods of heatwave.



In addition to the above steps, those of you with the additional feature of summer by-pass should operate it on manual mode – turning it on at night-time and off during the day.

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